EP1097954B1 - Process for the preparation of polyurethane foams - Google Patents

Description

The invention relates to a process for the production of polyurethane foam, in particular for the production of polyurethane integral foams. Polyurethane foams are usually prepared by mixing a polyisocyanate component of at least one di- or polyisocyanate with a polyol component of at least one polyether or polyester polyol in the presence of at least one catalyst and at least one blowing agent and optionally in the presence of various auxiliaries and additives well known in polyurethane chemistry. These additives may also include foam stabilizers.

By targeted use of low molecular weight diols as chain extenders or triols and amines as crosslinkers, the properties of PUR foams can be adjusted in a wide range.

A special variant of mold foaming is reaction foam casting, also referred to as RIM (reaction injection molding) process. There are obtained flexible to semi-rigid moldings of integral foam, for which it is characteristic that a compact edge zone with a lightweight cellular core is integrally connected within a molding of the same PUR material. Such moldings are used for example in the automotive industry in the field of car interior trim, dashboards, steering wheels, but also for spoilers, etc. Another important and important area of application is the shoe industry for shoe soles or shoe components. In many other areas, PU foams are used on a large scale today.

The blowing agents used are mainly carbon dioxide or haloalkanes. The selection of the blowing agent depends, inter alia, on the reaction mixture to be foamed and the desired strength and other properties of the finished foamed foam. For the production of harder polyurethane foams in addition to Wassser in particular chlorofluorocarbons (CFCs), Hydrogenfluorchlorkohlenwasserstoffe (HCFC), Hydrogenfluorkohlenwasserstoffe (HFCs) or special carbamates have been used as propellant. Because of the known ecological problems in connection with the said halogen-containing blowing agents, their use in the field of integral foams is constantly decreasing. However, the use of water as the sole propellant is not a solution to the propellant problem, especially because firstly the pressure reduction in the foam is much slower than when using the known halogen-containing propellant, so that in the series production usual short mold life resulting moldings that are prone to bursting, and second, the elasticity of the resulting molded body (especially in shoe soles) does not meet the requirements of practice.

The equally obvious idea of using hydrocarbons, such as e.g. The isomeric pentanes or cyclopentanes to solve the propellant problem is mainly associated with the problem of the flammability of the substances.

As catalysts for the production of polyurethane foams are mainly tertiary amines and organotin compounds. For the o.g. Integral foam systems are usually used tertiary amines. Co-catalysis by metal catalysts is possible. The foams produced with the aid of amine catalysts have various disadvantages. The amine catalysts remain in the foam, but are not firmly bound there, so that in the course of time, especially after heat storage, a long-lasting to constant odor evaporation is observed. The gradual gaseous exhalation of amines may also be associated with health hazards to consumers, so that it is an urgent need, inter alia, the automotive industry to have available amine-free PUR foams, particularly for the car interior lining. Furthermore, the foams produced with amine catalysts have the disadvantage that they lead to discoloration of the PVC when processed in particular as a laminate with PVC. The hitherto known incorporable amine catalysts all have the aforementioned technical disadvantages. They can lead to unpleasant odor or to PVC discoloration, because they partially evaporate during the reaction or the curing of the foam is insufficient.

The invention is therefore based on the object to provide a process for the production of polyurethane foam available in which can be dispensed with the concomitant use of fluorinated and / or chlorinated hydrocarbons as blowing agents and conventional amine catalysts. It is desirable that a significantly reduced PVC discoloration in heat storage and a significantly lower odor evaporation is achieved in moldings of appropriate hardness than in conventional moldings.

Surprisingly, it has now been found that certain carbamates of the type described in more detail below are catalysts and blowing agents, which in particular also allow the production of polyurethane foams of compact surfaces. In this case, the use of additional blowing agents can be completely or partially omitted. Moreover, conventional amine catalysts are completely replaced. However, co-catalysis with other polyurethane-catalyzing catalysts, for example certain metal catalysts, is possible.

Although EP-B 0 121 850 already describes the use of certain carbamates which carry hydroxyl groups, as blowing agents for polyurethane foams, these as shown in the exemplary embodiments, preferably in combination with other blowing agents are used. However, EP-B 0 121 850 gives no indication of the surprising finding that carbamates can also be used as catalysts for the production of polyurethane foams. Due to their special constitution, the specified carbamates can not replace the tertiary amine catalysts either.

EP-B-10652250 describes the use of hydroxyl-containing carbamates as the exclusive blowing agent for integral foams. Again, it is not about the replacement of catalysts, but rather catalysts are used, which are among the o.g. unwanted side effects, such as odor and PVC discoloration.

DE-A-195 29 412 and US-A-4 517 313 describe the preparation of carbamates in an aqueous solution. These carbamates are used as catalyst / blowing agent for the production of polyurethane foams.

wobei:

• R₁ und R₂ für gleiche oder verschiedene Alkylreste stehen,
• R₃ und R₄ für gleiche oder verschiedene Reste stehen und Wasserstoff oder Alkylreste bedeuten,
• R₅ Wasserstoff, einen Alkanolrest, einen Polyethermonoolrest oder den mit X gekennzeichneten Rest bedeutet
• n für 2 oder 3 steht,

unter Ausschluß sonstiger Aminkatalysatoren als Katalysator und zugleich als Treibmittel verwendet wird.To achieve the above object, the invention provides in a process for the preparation of polyurethane foam in the presence of at least one catalyst and at least one blowing agent that a carbamate or a mixture of carbamates of the general formula I.

in which:

• R ₁ and R _{2 represent} identical or different alkyl radicals,
• R ₃ and R _{4 represent} identical or different radicals and denote hydrogen or alkyl radicals,
• R _{5 is} hydrogen, an alkanol radical, a polyether monool radical or the radical indicated by X.
• n stands for 2 or 3,

excluding other amine catalysts as a catalyst and at the same time as a blowing agent is used.

The process leads to moldings which have significantly reduced PVC discoloration on heat storage and a significantly lower odor than moldings produced with conventional catalysts at the same hardness.

An alkanol radical is understood by the chemist to mean generally known groups, e.g. a methanol radical, ethanol radical, propanol radical, isopropanol radical (... * further alkanol radicals?).

"Alkyl radical" is understood to mean all groups which fall under the general chemical definition of an alkyl radical, in particular methyl radicals, ethyl radicals, propyl radicals, butyl radicals, isopropyl radicals, isobutyl radicals, tert-butyl radicals, cyclopropyl radicals, cyclopenthyl radicals, cyclohexyl radicals, cycloheptyl radicals and also long-chain branched or unbranched or cyclic alkyl radicals.

1. A) eine Polyisocyanatkomponente mit einem NCO-Gehalt von 14 bis 33, 6 Gew.-%, bestehend aus mindestens einem, ggf. modifizierten Polyisocyanat oder Polyisodyanatgemisch, der Diphenylmethanreihe;
2. B) eine Polyolkomponente einer mittleren Hydroxylfunktionalität von 2 - 3, bestehend aus wenigstens einem Polyether oder Polyesterpolyol mit OH-Zahlen < 56, ggf. unter Zusatz üblicher Hilfes- und Zusatzstoffe, wie sie aus der Polyurethanchemie bekannt sind.

Preferably, the process is characterized in that the polyurethane foam is prepared from a reaction mixture containing:

1. A) a polyisocyanate component having an NCO content of 14 to 33, 6 wt .-%, consisting of at least one, optionally modified polyisocyanate or Polyisodyanatgemisch, the Diphenylmethanreihe;
2. B) a polyol component of an average hydroxyl functionality of 2-3, consisting of at least one polyether or Polyester polyol with OH numbers <56, optionally with the addition of customary auxiliaries and additives, as are known from polyurethane chemistry.

More preferably, the reaction mixture may additionally contain crosslinking and / or chain extenders which are selected from at least one difunctional or trifunctional compound having an OH or NH number of 56 to 1810 in amounts of 1 to 20 wt .-% based on the weight of Polyol component (B) exist.

The polyisocyanate component A) is preferably liquid at 20 ° C and has an NCO content of 14 to 33.6, preferably from 20 to 30 wt .-%, on. It is at least one, optionally chemically modified, polyisocyanate or Polyisocyanatgemisach the diphenylmethane series.

These include in particular 4,4'-diisocyanatodiphenylmethane, its technical mixtures with 2,4'-diisocyanatodiphenylmethane and optionally 2,2'-diisocyanatodiphenylmethane, mixtures of these diisocyanates with their higher homologs, as obtained in the phosgenation of aniline / formaldehyde condensates and / or obtained in the distillative workup of such Phosgenierungsprodukten to understand. The "chemical modification" of these polyisocyanates is in particular the urethane modification known per se, e.g. by reacting up to 30 equivalent percent of the present NCO groups with polypropylene glycols having a maximum molecular weight of 700 or a per se known carbodiimidization of up to 30% of the present NCO groups. Allophanate or biuret modifications of said isocyanates are also possible according to the invention.

Component B) has an average hydroxyl functionality of from 2 to 3 and consists of at least one polyhydroxypolyether having a molecular weight of 2,000 to 10,000, preferably 3,000 to 6,000 and / or at least one polyhydrosypolyether having a molecular weight of 2,000 to 10,000, preferably 2,000 to 4,000 Molecular weight refer to the molecular weight which can be calculated from OH functionality and OH content.

Suitable polyhydroxypolyethers are the alkoxylation products of preferably di- or trifunctional starter molecules known per se from polyurethane chemistry, or mixtures of such starter molecules. Examples of suitable starter molecules are water, ethylene glycol, diethylene glycol, propylene glycol, trimethylolpropane or glycerol. Alkylene oxides used for the alkoxylation are, in particular, propylene oxide and ethyoxide, these alkylene oxides being able to be used in any order and / or as a mixture. Alkoxylation products formed by the reaction of a starter with tetrahydrofuran can also be used (PTMEG).

Suitable polyester polyols are the per se known, hydroxyl-containing esterification products of preferably dihydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol with minor amounts of preferably difunctional carboxylic acids such as succinic acid, adipic acid, phthalic acid, tetrahydrophthalic acid, Hexahydrophthalic acid or mixtures of such acids.

The difunctional or trifunctional chain extenders or crosslinkers are preferably those having a molecular weight range of 62 to 1999, preferably 62 to 400. In the case of non-defined compounds, this value also refers to that of OH functionality in terms of molecular weight value and OH number calculated value.

Preferred chain extenders (C) include simple dihydric alcohols of less than 200 molecular weight such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol or mixtures of such simple diols. Also suitable as component C) or as part of component C) are the statements made with regard to the molecular weight, diols containing ether groups, such as they are accessible by propoxylation and / or ethoxylation of divalent starter molecules of the type already mentioned above by way of example.

Also suitable as chain extenders C) are aromatic diamines having sterically hindered amino groups, in particular 1-methyl-3,5-diethyl-2,4-diaminobenzene and its technical mixtures with 1-methyl-3,5-diethyl-2,6-diaminobenzene (DETDA).

Furthermore, functional compounds, in particular trifunctional alcohols such as glycerol, trimethylolpropane, hexanetriol (2,2,6), butantriol (1,2,4) can be used as a crosslinking agent as a crosslinking agent.
Alkanolamines such as mono-, di-triethanolamine. Diisopropanolamine and others are also suitable.
Any mixtures of the exemplified chain extenders may also be used.

The chain extenders or crosslinkers C) are used in the process according to the invention in amounts of 1 to 20, preferably 4 to 12 wt .-%, based on the weight of components B).

As auxiliaries and additives, on the one hand, the carbamates essential to the invention and, on the other hand, additives of the type known per se are used. '

The carbamates essential to the invention are compounds of the abovementioned general formula, where the variables R ₁ to R ₅ and n have the abovementioned meaning.

wobei:

• R₅ Wasserstoff, eine Alkylrest oder den mit X gekennzeichneten Reste bedeuten.
• R₁ und R₂ Methylreste bedeuten.
• R₃ und R₄ Wasserstoff bedeuten und
• n für 3 steht.

Preferably, such carbamates of the following general formula are used,

in which:

• R _{5 is} hydrogen, an alkyl radical or the radicals marked X.
• R ₁ and R _{2 are} methyl radicals.
• R ₃ and R _{4 are} hydrogen and
• n stands for 3.

mit gasförmigen oder festem Kohlendioxid bei Temperaturen zwischen 40 und 130°C mit oder ohne Verwendung eines geeigneten Verdünnungsmittel erfolgen.The preparation of the carbamates can be achieved by simple saturation of the underlying diamines of the formula

with gaseous or solid carbon dioxide at temperatures between 40 and 130 ° C with or without the use of a suitable diluent.

Particularly preferred are 3-dimethylamino propyl amine and bis (3-dimethylamine propyl) amine for the preparation of carbamates or mixtures of these amines.

In carrying out the process according to the invention, the carbamate used as propellant is in an amount of less than 8 wt .-%, preferably 0.1 to 6, preferably 0.5 to 5 wt .-%, based on the weight of component B) , used.

Further auxiliary agents and additives (D) which may be used are those customary in the production of polyurethane foams, for example activators, stabilizers or other halogen-free blowing agents, in particular water, which may be present in an amount of up to 0.5% by weight on the weight of component B), be used.

Preferably, however, the process according to the invention is carried out with total amounts of water of about 0.1% by weight.

Incidentally, the starting components are used in amounts corresponding to an isocyanate index of 80 to 120, preferably 95 to 105.

for carrying out the process according to the invention, the components B) to D) are generally combined to form a "polyol component", which is then mixed with the polyisocyanate component A) and is preferably reacted in closed forms. Here one uses usual measuring and Dosierungsvörrichtugnen. As molds, for example, shoe soles or Schuhbauteilformen be used (for the production of shoe soles or shoe components after the casting or Direktbesohlungsverfahren), steering wheel or Spoilerformen or forms for protective pad in the car interior, the inner walls are often coated before filling the mold with conventional mold release agents.

For the preparation of other Schumstoffteile, such as free-blown blocks, conventional, known casting, spraying or other methods are used.

The temperature of the reaction components (polyisocyanate component A) or polyol component) is generally within the temperature range of 20 to 45 ° C. The temperature of the molds is generally at 20 to 70 ° C.

The amount of the foamable material introduced into the mold is such that the densities of the moldings of 200 to 700 kg / m ³ result.

In a further development of the method, at least one further blowing agent may additionally be used, wherein preferably the blowing agents already known from polyurethane chemistry are used. Furthermore, it is additionally possible to use at least one further co-catalyst, preferably a metal catalyst such as, for example, dibutyltin dilaurate or tin dioctoate.

The method can preferably be used for the production of foam sheathing, of steering wheels, spoilers, as well as protective pads in car interiors. In addition, the production of shoe soles or shoe components, in particular by the casting or direct coating method is possible. The process products of the invention may be formed as soft, hard or semi-rigid polyurethane foams. Preferably, they are semi-rigid polyurethane foams with a compact surface of hardness range Shore A 20 to 80. In the examples below, all percentages are by weight.

Examples raw materials Polyisocyanate 1:

Polyisocyanate mixture having an NCO content of 28% and a viscosity of 130 mPa s, consisting of equal parts by weight of (i) a polyisocyanate having an NCO content of 24.5% and a viscosity (25 ° C) of 500 mPa s, the by phosgenation of an aniline / formaldehyde condensate and subsequent reaction of the phosgenation product with polypropylene glycol of OH number 515, and (ii) a polyisocyanate mixture of the diphenylmethane series having an NCO content of 31.5% and a content of diisocyanatodiphenylmethane isomers of 60% and higher nuclear homogeneity of 40%.

Polyisocyanate 2:

Modified 4,4'MDI with an NCO content of 30%, which is prepared by partial carbodiimidization of the NCO groups.

Polyol 1:

Polyether triol of OH number 36, prepared by propoxylation of trimethylolpropane with subsequent ethoxylation of the propoxylation product (PO: EO weight ratio ≅ 85:15)

Polyol 2:

Polyether triol of OH number 28, prepared by propoxylation of trimethylolpropane with subsequent ethoxylation of the propoxylation product (PO: EO weight ratio ≅ 85:15) grafted with 20 wt .-% styrene / acrylonitrile (weight ratio ≅ 40:60).

Carbamate 1:

In 400 g of 3-dimethylaminopropyl amine in 400 g of ethylene glycol is introduced to saturation CO ₂ . The absorbed CO ₂ mass is 156 g and the viscosity 1500 mPa s.

Carbamate 2:

Into 400 g of bis (3-dimethylaminopropyl) amine in 400 g of ethylene glycol is introduced to saturation CO ₂ . The absorbed CO ₂ mass is 94 g and the viscosity 672 mPa s.

Carbamate 3 (not according to the invention):

In 750 g of aminoethanol are introduced to saturation 220g CO ₂ , the viscosity of this compound is 22000 mPa s. This product is diluted with 750 g of ethylene glycol to carbamate III.

The odor was determined according to VDA recommendation 270 variant B-3. The grade 1 is not perceptible and the grade 6 unbearable.

The PVC discoloration was determined after contact heat storage based on the VW Central Standard PV 3355. To avoid cross-contamination, the samples were each stored separately in a 1.5 liter glass vessel in a forced air oven at 115 ° C for 72 h.

example 1

About a customary for the production of steering wheels Krauss Maffei type RIM Star 12 with Umlenkmischkopf a foamable mixture of the following quantity is entered in a production standard steering wheel shape so that a gross density of 500kg / m ³ results.

Mold temperature 45 ° C, raw material temperature 30 ° C, mold life 2.5 min, shot time 5s, discharge rate 153g / s, part weight (without insert) 699g, flash 74g.

The interior walls of the mold are sprayed with a commercially available mold release agent (Acmosil 36-4536). polyol Polyol 1 80 parts by weight. Polyol 2 10 parts by weight. ethylene glycol 6.05 parts by weight. diethanolamine 0.45 parts by weight. Formrez UL 28 * 0.013 parts by weight. water 0.1 parts by weight. Carbamate I 2.0 parts by weight. * Commercial product of Witco polyisocyanate Polyisocyanate 1 26.5 parts by weight. Polyisocyanate 2 26.5 parts by weight. properties PVC discoloration hardly recognizable Hardness (Shore A) 56 flow behavior Well Odor (VDA 270 (B3)) 2.5

The steering wheel visually meets the high demands on a steering wheel.

Example 2

About a customary for the production of steering wheels Krauss Maffei type RIM Star 12 with Umlenkmischkopf a foamable mixture of the following quantity is entered in a production standard steering wheel shape so that a gross density of 500kg / m ³ results.

Mold temperature 45 ° C, raw material temperature 30 ° C, mold life 2.5 min, shot time 5s, output 153g / s, part weight (without insert) 625g, flash 120g.

The interior walls of the mold are sprayed with a commercially available mold release agent (Acmosil 36-4536). polyol Polyol 1 80 parts by weight. Polyol 2 10 parts by weight. ethylene glycol 6.05 parts by weight. diethanolamine 0.45 parts by weight. Formrez UL 28 * 0.013 parts by weight. water 0.1 parts by weight. Carbamate I 2.0 parts by weight. Carbamate III 0.5 parts by weight. * Commercial product of Witco polyisocyanate Polyisocyanate 1 27.5 parts by weight. Polyisocyanate 2 27.5 parts by weight. properties Hardness (Shore A) 55 PVC discoloration hardly recognizable flow behavior Very well Odor (VDA 270 (B3)) 1.5

The steering wheel visually meets the high demands on a steering wheel.

Example 3

About a standard for the production of Lenrädern Krauss Maffei high pressure machine of the type RIM Star 12 with Umlenkmischkopf a foamable mixture of the following quantity is entered in a production standard steering wheel shape so that a bulk density of 500kg / m ³ results.

Mold temperature 45 ° C, raw material temperature 30 ° C, mold life 2.5 min, shot time 5s, output 153g / s, part weight (without insert) 763g, flash 10g.

The interior walls of the mold are sprayed with a commercially available mold release agent (Acmosil 36.4536). polyol Polyol 1 80 parts by weight. Polyol 2 10 parts by weight. ethylene glycol 6.05 parts by weight. diethanolamine 0.45 parts by weight. Formrez UL 28 * 0.013 parts by weight. water 0.1 parts by weight. Carbamate II 1.5 parts by weight. Carbamate III 0.5 parts by weight. polyisocyanate Polyisocyanate 1 27.5 parts by weight. Polyisocyanate 2 27.5 parts by weight. properties Hardness (Shore A) 54 PVC discoloration hardly recognizable flow behavior Well Odor (VDA 270 (B3)) 1.5 * Commercial product Witco

The steering wheel visually meets the high demands on a steering wheel.

Example 4

About a customary for the production of steering wheels Krauss Maffei type RIM Star 12 with Umlenkmischkopf a foamable mixture of the following quantity is entered in a production standard steering wheel shape so that a gross density of 500kg / m ³ results.

Mold temperature 45 ° C, raw material temperature 30 ° C, mold life 2.5 min, shot time 5s, output 153g / s, part weight (without insert) 625g, flash 120g.

The interior walls of the mold are sprayed with a commercially available mold release agent (Acmosil 36-4536). polyol Polyol 1 80 parts by weight. Polyol 2 10 parts by weight. ethylene glycol 6.05 parts by weight. diethanolamine 0.45 parts by weight. Formrez UL 28 * 0.013 parts by weight. water 0.1 parts by weight. Carbamate I 2.5 parts by weight. Carbamate III 1.0 parts by weight. * Commercial product of Witco polyisocyanate Polyisocyanate 1 27.5 parts by weight. Polyisocyanate 2 27.5 parts by weight. properties Hardness (Shore A) 57 PVC discoloration hardly recognizable flow behavior Very well odor 2.0

The steering wheel visually meets the high demands on a steering wheel.

Comparative Example 5

About a customary for the production of steering wheels Krauss Maffei type RIM Star 121 with Umlenkmischkopf a foamable mixture of the following quantity is entered in a production standard steering wheel shape so that a gross density of 500kg / m ³ results.

Mold temperature 45 ° C, raw material temperature 30 ° C, mold life 2.5 min, shot time 5s, output 153g / s, part weight (without insert) 675g, shoot 97g.

The inner walls of the mold are sprayed with a commercially available mold release agent (Acmosil 36-4536). polyol Polyol 1 80 parts by weight. Polyol 2 10 parts by weight. Ethylenglyikol 6.18 parts by weight. diethanolamine 0.45 parts by weight. Formrez UL 28 ² 0.013 parts by weight. triethylenediamine 0.07 parts by weight. Toyocat EF ³ 0.2 parts by weight. Toyocat MR ³ 0.4 parts by weight. water 0.1 parts by weight. Carbamate III 2.0 parts by weight. ² commercial product of Witco
³ commercial products of Toyosoda (special tertiary amines) polyisocyanate Polyisocyanate 1 27.1 parts by weight. Polyisocanate 2 27.1 parts by weight. properties Hardness (Shore A) 57 PVC discoloration red flow behavior Very well Odor (VDA 270 (B3)) 4.0

The steering wheel visually meets the high demands on a steering wheel.

Claims (9)

1. Process for producing polyurethane foam in the presence of at least one catalyst and of at least one propellant, characterized in that
   a carbamate or a mixture of carbamates of the general formula I

   

   where:

   R₁ and R₂ represent the same or different alkyl radicals,

   R₃ and R₄ represent the same or different radicals and denote hydrogen or alkyl radicals,

   R₅ denotes hydrogen, an alkanol radical, a polyether monool radical or the radical characterized by X, n represents 2 or 3,

   is used as catalyst and propellant, essentially excluding other amine catalysts and in the absence or presence of up to 0.5 wt.% of water based on the component consisting of polyol and if appropriate additives.
2. Process according to Claim 1, characterized in that the polyurethane foam is produced from a reaction mixture which contains:

   A) a polyisocyanate component having an NCO content of 14 to 33.6 wt.%, consisting of at least one modified or unmodified polyisocyanate or polyisocyanate mixture of the diphenylmethane series;

   B) a polyol component having an average hydroxyl functionality of 2 - 3, consisting of at least one polyether or polyester polyol having OH numbers < 56, optionally with addition of conventional auxiliaries and additives, as are known from polyurethane chemistry.
3. Process according to Claim 2, characterized in that the reaction mixture also contains at least one crosslinking or chain-extending agent of at least one difunctional or trifunctional compound having an OH or NH number of 56 to 1810 in quantities of 1 to 20 wt.% based on the weight of the polyol component.
4. Process according to any one of Claims 1 to 3, characterized in that it further utilizes at least one additional propellant.
5. Process according to any one of Claims 1 to 4, characterized in that it further utilizes at least one additional co-catalyst, preferably a metal catalyst.
6. Process according to any one of Claims 1 to 5, characterized in that the carbamates are used in a quantity of less than 8 wt.% based on the weight of the polyol component (B).
7. Use according to any one of Claims 1 to 6, characterized in that the polyurethane foam is shaped by transforming the reaction mixture in closed moulds to form cellular mouldings having a compact surface (integral foams).
8. Process according to Claim 7, characterized in that the polyurethane foam is shaped to form foam coverings of steering wheels, spoilers, as well as car interior crash padding.
9. Process according to any one of Claims 1 to 8, characterized in that the polyurethane foam is shaped to form shoe soles or shoe components by the casting or direct-coating process.